Ensure to_dict() returns auth_tok
Ensure to_dict() returns auth_tok

* ReddwarfContext was changed to defer to the parent's to_dict method.
  When the context is serialized to amqp, it is known by the key 'auth_token'
  instead of the expected 'auth_tok' as a side-effect.

fixes bug 1152827

Change-Id: I8fcdb2a3eaf8da0dda3c0229b24e32f528353619

openstack/trove,citrix-openstack/build-trove,changsimon/trove,zhangg/trove,mmasaki/trove,citrix-openstack/build-trove,zhujzhuo/openstack-trove,citrix-openstack-build/trove,changsimon/trove,fabian4/trove,zhujzhuo/openstack-trove,redhat-openstack/trove,redhat-openstack/trove,cp16net/trove,mmasaki/trove,changsimon/trove,cp16net/trove,hplustree/trove,citrix-openstack/build-trove,zhangg/trove,redhat-openstack/trove,mmasaki/trove,citrix-openstack-build/trove,denismakogon/trove-guestagent,hplustree/trove,denismakogon/trove-guestagent,zhujzhuo/openstack-trove,openstack/trove,citrix-openstack-build/trove,fabian4/trove,fabian4/trove,cp16net/trove